BIO PSYCH - LECTURE 1: HISTORY AND INTRO TO NEURONS

trephination

An ancient surgical procedure that involves drilling a hole into the skull, often believed to release evil spirits or alleviate pressure from head injuries.

phrenology

the idea that different bumps on the skull could reveal our cognitive abilities and character traits

equipotentiality

the hypothesis that all parts of the brain contribute equally to certain functions and that specific functions are not localized to any one area

golgi staining

A staining technique invented by Camillo Golgi that stains about 5% of neurons. This allowed individual neurons to be visible for the first time. Cajal used this method to develop the Neuron Doctrine

synapse

The junction where information passes from one neuron to another. Electrical signals travel within neurons; chemical signals travel between them

nucleus

Organelle in the soma that contains DNA and regulates gene expression.

ribosomes

Structures that synthesize proteins from mRNA—critical for neuron function since neurons rely on constant production of proteins such as channels and receptors

cell theory

Proposed by Schleiden and Schwann:

• All living organisms are composed of cells.

• Cells come from pre-existing cells.

• The cell is the smallest unit of life.
  Originally thought NOT to apply to the nervous system.

neuron doctrine

Proposed by Ramón y Cajal:

• The nervous system is composed of individual, discrete cells called neurons.

• Neurons are not physically continuous (contradicts Golgi’s Reticular Theory).

• Neurons communicate at synapses but maintain separate boundaries

neurons

Electrically excitable, polarized cells that receive, integrate, and send information using both electrical and chemical signals. They have specialized functional regions

axon

A long projection that carries information away from the soma. It conducts electrical impulses (action potentials) over long distances to synaptic terminals

dendrite

Branch-like projections that receive input from other neurons and transmit that information toward the soma

soma

The cell body; the metabolic center containing the nucleus, organelles, and machinery for protein synthesis. Integrates incoming signals

synaptic terminal

The end of an axon where neurotransmitters are released to communicate with another neuron, muscle, or gland

Law of Dynamic Polarization

Created by Cajal. States that information always travels in one direction within a neuron:
Dendrites → Soma → Axon → Synaptic Terminal, and from presynaptic neuron → postsynaptic neuron